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Finding the Fourth Proportional to 209.76, 312.08 and 205.66

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Solution

The fourth proportional to 209.76, 312.08 and 205.66 is: 305.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.76 : 312.08 = 205.66 : x
  2. Step 2: Convert to fraction form
    209.76/312.08 = 205.66/x
  3. Step 3: Cross multiply
    209.76x = 312.08 × 205.66
  4. Step 4: Simplify right side
    209.76x = 64,182.37
  5. Step 5: Solve for x
    x = 64,182.37/209.76
  6. Step 6: Final answer
    x = 305.98

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.